A critical need exists to develop imaging agents which can diagnose and/or monitor infections in tissue in a patient. Currently, most imaging is based on the detection of mass infection or general metabolic activity. Imaging agents that elucidate the pathobiology of cells in the masses are lacking. An allosteric inhibitor of LFA-1 has been developed, the small molecule alkyl-amino-NorBirt. Determination of its structure activity relationship has permitted modifications allowing radiometal attachment through an alkylamino linker. We postulate that radiolabeled alkyl-amino-NorBirt will retain its binding affinity towards LFA-1 and thus can be used as a non-invasive imaging agent for a number of disease states and infections caused by microbial agents such as bacteria, viruses, fungi and parasites and other. Our previous work has demonstrated that the radiometal, 213Bi, can be effectively incorporated into the alkyl-amino-NorBirt. We propose to link a radiometal with good imaging characteristics to image LFA-1 overexpression in infected tissues. The radiolabeled compound will allow imaging of infected cells, diagnosis and staging, as well as monitoring responses to other therapeutic interventions.